1. Field of the Invention
The present invention generally relates to an adapter for interconnecting a fluid container with an administration feeding set, and more particularly to an adapter having a retractable spike for use with a feeding system.
2. Prior Art
Feeding systems are frequently used to provide nutrition through either enteral or parenteral access to a patient unable to take nutrition orally. As used herein, the term nutrition shall be interpreted to include nutrition, medication and hydration. These feeding systems typically comprise an administration feeding set attached to a source of nutrition at one end and some kind of tube arrangement at the other end for providing nutrition immediately to a patient. In enteral feeding, the nutrition is typically administered to the patient by accessing a digestive organ through use of a nasogastric or gastrostomy tube which terminates in the stomach, or a nasojejunal or jejunostomy tube which terminates in the jejunum. In contrast, parenteral feeding typically includes feeding nutrition by injection into a vein. Such feeding systems also include fluid containers which hold nutritional fluid in liquid form and typically include an opening sealed with a flexible membrane to seal and isolate the contents from environmental contaminants.
Often fluid containers of the above-mentioned character are connected to the administration feeding set by an adapter. One such adapter typical of the prior art is disclosed in U.S. Pat. No. 4,567,999 to Hjertman et al. entitled “Self-adhesive Connecting Device.” Hjertman discloses an adapter for providing a sealed liquid connection with the orifice of a fluid container formed from a flexible sheet material. The adapter includes a hollow chamber with an outside surface adapted to be adhered to the container wall and a sharp point that is encased therein which is operative to penetrate the wall of the container. A pressure sensitive adhesive is provided on the outer peripheral surface of the Hjertman adapter that is intended to attach the adapter to the container wall such that the hollow chamber is sealed from outside contaminates.
Although the device of Hjertman et al. effectively provides a sealed liquid connection with a container, such devices also have several inherent drawbacks. Because the device to Hjertman entirely encloses the sharp point within the chamber, the user of these devices would need to apply a sufficiently strong exterior force to the chamber in order to actuate the device. However, directly exerting an exterior force upon the chamber to actuate the device increases the possibility of rupturing the chamber and resulting in mechanical failure of the device. Moreover, inadvertent impacts upon the chamber during transportation and storage are also likely to result in premature rupturing of the chamber. Finally, properly adhered to the container, such devices cannot be easily reused with other fluid containers.
Other connection devices have been suggested to further advance the art. For instance, U.S. Pat. No. 5,041,105 to D'Alo et al. entitled “Vented Spike Connection Component,” which is assigned to the assignee of the present invention, discloses a connection component suitable for use with a feeding system which includes a fluid container having a cap with an orifice and external threading disposed about the cap. A foil, or other similar frangible material, seals off the orifice of the container from fluid flow and outside contaminants. The connection component includes internal threading that mates with the external threading of the cap and a projecting spike which is adapted to penetrate the foil seal and establish fluid flow as the connection component is attached to the fluid container and actuated.
Although the D'Alo et al. device substantially advances the art, such connection components could still be further improved upon. The device to D'Alo et al. relies solely on frictional engagement between the threaded portion of the housing body and the threaded portion of the cap to create and maintain a fluid-tight seal. The device to D'Alo et al. also operates to simultaneously pierce the container when the user connects the connection component, and thus the operator must interconnect the device at the precise moment when it is desired to establish fluid flow. In other words, the operator cannot attach the D'Alo et al. device to the pre-filled container without instantaneously piercing the foil seal and establishing fluid flow which may be undesirable. Accordingly, the operator must delay attaching the device to the container until needed, or the operator must attach the device to the fluid container and immediately establish fluid flow when the foil seal is pierced by the device connection.
Therefore, one skilled in the art can best appreciate that several advances would still be desirable. It would be desirable to have a connection device that may be properly secured to the container, while allowing the operator to delay piercing the fluid container and establish fluid flow when needed. It would also be desirable to have a connection device which provides a leak-free seal at all times between the fluid container, the connection device, and the administration feeding set. It would be further desirable to have a spike of the connection device which is shielded from touch contamination by the user.